Report more Garbage Collection allocation statistics.

.github/workflows/main.yml

@@ -15,12 +15,13 @@ jobs:
     strategy:
       matrix:
         ocaml-compiler:
+          - 5.0
           - 5.1
           - 5.2
           - 5.3
         os:
           - ubuntu-latest
-          - macos-15
+          - macos-latest
 
     runs-on: ${{ matrix.os }}
 

.ocamlformat

@@ -1,4 +1,4 @@
 version = 0.27.0
 profile = conventional
 
-ocaml-version = 5.2.0
+ocaml-version = 5.0.0

README.md

@@ -68,6 +68,15 @@ Percentile       Latency (ms)
 99.9990          72.55
 99.9999          72.55
 100.0000         72.55
+
+GC allocations (in words):
+Total heap:	 501516808
+Minor heap:	 602373895
+Promoted words:	 100857087 (16.74%)
+
+Minor Gen: 904 collections
+Major Gen: 34 collections 0 forced collections
+Compactions: 0
 ```
 
 ### Tracing a program

dune-project

@@ -3,6 +3,7 @@
 (name runtime_events_tools)
 (version "0.5.1")
 (generate_opam_files true)
+(cram enable)
 
 (source
  (github tarides/runtime_events_tools))
@@ -18,7 +19,7 @@
  (depends
   (ocaml (>= "5.0.0~"))
   hdr_histogram
-  (cmdliner (>= 1.1.0))
+  (cmdliner (>= 1.3.0))
   (trace-fuchsia (>= 0.10))
   (trace (>= 0.10))
   (menhir :with-test)
@@ -31,4 +32,4 @@
  (description "Various tools for the runtime events tracing system in OCaml: minimal dependencies")
  (depends
   (ocaml (>= "5.0.0~"))
-  (cmdliner (>= 1.1.0))))
+  (cmdliner (>= 1.3.0))))

lib/olly_common/cli.ml

@@ -44,6 +44,22 @@ let freq_option =
     & opt float 0.1 (* Poll at 10Hz by default. *)
     & info [ "freq" ] ~docv:"freq" ~doc)
 
+let runtime_events_dir =
+  let doc =
+    "Sets the directory where the .events files containing the runtime event \
+     tracing system’s ring buffers will be located.\n\n\
+    \               If not specified a temporary directory will be used."
+  in
+  Arg.(value & opt (some string) None & info [ "d"; "dir" ] ~docv:"dir" ~doc)
+
+let runtime_events_log_wsize =
+  let doc =
+    "Size of the per-domain runtime events ring buffers in log powers of two \
+     words. Defaults to 16."
+  in
+  Arg.(
+    value & opt (some int) None & info [ "log-wsize" ] ~docv:"log-wsize" ~doc)
+
 let exec_args p =
   let exec_and_args, ea_docv =
     let doc = "Executable and arguments to trace." in

lib/olly_common/launch.ml

@@ -8,19 +8,23 @@ type subprocess = {
   pid : int;
 }
 
+type runtime_events = { log_wsize : int option; dir : string option }
 type exec_config = Attach of string * int | Execute of string list
 
 (* Raised by exec_process to indicate various unrecoverable failures. *)
 exception Fail of string
 
-let exec_process (argsl : string list) : subprocess =
-  if not (List.length argsl > 0) then
+let exec_process (config : runtime_events) args =
+  if not (List.length args > 0) then
     raise (Fail (Printf.sprintf "no executable provided for exec_process"));
 
-  let executable_filename = List.hd argsl in
+  let executable_filename = List.hd args in
 
-  (* TODO Set the temp directory. We should make this configurable. *)
-  let dir = Filename.get_temp_dir_name () |> Unix.realpath in
+  let dir =
+    match config.dir with
+    | None -> Filename.get_temp_dir_name () |> Unix.realpath
+    | Some path -> Unix.realpath path
+  in
   if not @@ Sys.file_exists dir then
     raise (Fail (Printf.sprintf "directory %s does not exist" dir));
   if not @@ Sys.is_directory dir then
@@ -29,15 +33,23 @@ let exec_process (argsl : string list) : subprocess =
   let env =
     Array.append
       [|
+        (* See https://ocaml.org/manual/5.3/runtime-tracing.html#s:runtime-tracing-environment-variables *)
         "OCAML_RUNTIME_EVENTS_START=1";
         "OCAML_RUNTIME_EVENTS_DIR=" ^ dir;
         "OCAML_RUNTIME_EVENTS_PRESERVE=1";
+        ((* See https://ocaml.org/manual/5.3/runtime.html#s:ocamlrun-options *)
+         let log_wsize =
+           match config.log_wsize with
+           | Some i -> "e=" ^ Int.to_string i
+           | None -> ""
+         in
+         "OCAMLRUNPARAM=" ^ log_wsize);
       |]
       (Unix.environment ())
   in
   let child_pid =
     try
-      Unix.create_process_env executable_filename (Array.of_list argsl) env
+      Unix.create_process_env executable_filename (Array.of_list args) env
         Unix.stdin Unix.stdout Unix.stderr
     with Unix.Unix_error (Unix.ENOENT, _, _) ->
       raise
@@ -74,9 +86,9 @@ let attach_process (dir : string) (pid : int) : subprocess =
   and close () = Runtime_events.free_cursor cursor in
   { alive; cursor; close; pid }
 
-let launch_process (exec_args : exec_config) : subprocess =
+let launch_process config (exec_args : exec_config) : subprocess =
   match exec_args with
-  | Execute argsl -> exec_process argsl
+  | Execute argsl -> exec_process config argsl
   | Attach (dir, pid) -> attach_process dir pid
 
 let collect_events poll_sleep child callbacks =
@@ -99,6 +111,8 @@ type consumer_config = {
   init : unit -> unit;
   cleanup : unit -> unit;
   poll_sleep : float;
+  runtime_events_dir : string option;
+  runtime_events_log_wsize : int option;
 }
 
 let empty_config =
@@ -111,12 +125,21 @@ let empty_config =
     init = (fun () -> ());
     cleanup = (fun () -> ());
     poll_sleep = 0.1 (* Poll at 10Hz *);
+    runtime_events_dir = None (* Use default tmp directory *);
+    runtime_events_log_wsize = None;
+    (* Use default size 16. *)
   }
 
-let olly config (exec_args : exec_config) =
+let olly config exec_args =
   config.init ();
   Fun.protect ~finally:config.cleanup (fun () ->
-      let child = launch_process exec_args in
+      let runtime_config =
+        {
+          dir = config.runtime_events_dir;
+          log_wsize = config.runtime_events_log_wsize;
+        }
+      in
+      let child = launch_process runtime_config exec_args in
       Fun.protect ~finally:child.close (fun () ->
           let callbacks =
             let {

lib/olly_gc_stats/dune

@@ -2,3 +2,19 @@
  (name olly_gc_stats)
  (optional)
  (libraries olly_common hdr_histogram))
+
+(rule
+ (deps olly_gc_stats.5.0.ml)
+ (target olly_gc_impl.ml)
+ (enabled_if
+  (< %{ocaml_version} 5.3))
+ (action
+  (copy %{deps} %{target})))
+
+(rule
+ (deps olly_gc_stats.5.3.ml)
+ (target olly_gc_impl.ml)
+ (enabled_if
+  (>= %{ocaml_version} 5.3))
+ (action
+  (copy %{deps} %{target})))